Apple Final Cut Pro 7 User Manual
Page 1419
Final Cut Pro analyzes a sequence to determine the processor workload required for
playback. Different portions of a sequence may require different amounts of processing.
Final Cut Pro breaks the sequence into segments and then indicates the processor
workload for each segment with a colored status bar. For more information, see
Status bars in the
Timeline indicate the
workload for each
segment; the upper bar
is for video, and the
lower bar is for audio.
For example: You edit a DV clip into a sequence. Final Cut Pro adds up the processor
“expenses” of reading the media file from your hard disk and decompressing the DV
frames. Because these processor “expenses” are fairly low, the color of the status bar over
that clip in the Timeline indicates that real-time playback is possible.
Now you add a color correction filter to a clip. Playback of this clip is now more “expensive”
for the processor because more calculations must be performed to display the result.
Final Cut Pro compares the number of required calculations to the speed of your
computer’s processor. If the processor “expenses” are low enough, the clip can still be
played in real time, even with the additional color correction filter.
Achieving Real-Time Playback When Processor Power Is Exceeded
As you add more effects to a clip, more processing power is required to play that segment
of the sequence. If too many effects are added, Final Cut Pro recognizes that the number
of calculations is too “expensive” for the processor, and the color of the status bar changes
to indicate that playback may still be in real time but no longer at full quality.
To keep your edit session moving and render-free, Final Cut Pro has several real-time
playback settings that balance playback quality with a minimum of dropped frames. For
a complete explanation of real-time playback settings, see
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Chapter 84
Using RT Extreme